PURPOSE: To prevent a restoration disable state by making a specific processing ineffective when the specific processing is designated at the same time by plural data communication equipments.

CONSTITUTION: When an operation section 3 of a corresponding time division multiplex device applies special operation, an operation detecting section 2 stores the operation and an operation section 1 outputs an operation inhibit request to the other time division multiplexer. If a reception signal requesting the operation inhibition is received from the other time division multiplexer within a prescribed time after a signal requesting the operation inhibition is transmitted, an operation channel section 4 of the control section 1 makes the operation of the own operating section 3 ineffective and a request releating the operation inhibition of the opposite device is outputted via an operation inhibition release signal transmission section 5.